The APS Conference on "Aldosterone and ENaC: from Genetics to Physiology" is scheduled for September 10-14, 2003 in Banff, Canada. The Conference combines two related fields with substantial scientific overlap: epithelial Na channels (ENaC) and the actions of aldosterone. Aldosterone is the most physiologically relevant and intensively studied stimulus of sodium reabsorption. It activates both ENaC and Na/K-ATPase in the kidney and distal colon. By regulating ENaC, aldosterone is the primary hormone that controls total body sodium balance and consequently is the major hormone that controls blood volume and, therefore, in mammals, controls mean blood pressure. Thus, abnormalities in aldosterone regulation of ENaC have profound implications for understanding the underlying causes of essential hypertension and related renal pathology. The Conference is expected to attract about 300 scientists to share in discussions about the central theme of amiloride-sensitive Na+ channels, their regulation, and their involvement in normal and pathophysiological situations, with an emphasis on the role of aldosterone in regulating these processes. The Conference is the fourth in a highly successful series held at 3 year intervals and has many of the same features, modified however by scientific progress, the desire to feature younger investigators and promote gender balance, by more time for attendee poster research presentations, and by specifically allocated time for informal interactions among Conference participants. In contrast to large, multi-society meetings like the Experimental Biology meeting, there is an exclusive focus on ENaC and aldosterone with particular emphasis on the role that ENaC and aldosterone regulation may play in the pathophysiology of high blood pressure and kidney and lung injury. This conference has the goal of providing the only focused meeting with critical mass of investigators examining ENaC or aldosterone so that two naturally allied areas can share information. One quarter of the 54 invited speakers and one of the organizers are female, and 45% are at the Assistant or Associate professor level. To increase the number of presentations by trainees or young investigators, 5-6 poster presenters will also present talks in the regular sessions. There will be a strong student awards program (12 awardees to be selected on the basis of merit). The success of three preceding meetings attests to its need and value to the scientific community.